Fire Extinguisher Types, Colours and a Guide to Their Use

Providing fire extinguishers in and around your commercial premises is both a safety necessity and a legal requirement. However having the correct fire extinguishers in place to tackle the most likely causes of fire in your place of work is not subject to laws but is down to individual research. Knowing which type of extinguisher to use for which class of fire, and, as importantly, which extinguisher type NOT to use could be the difference between life and death and averting a fire catastrophe.

Here at Seton we offer every type of Fire Extinguisher and this simple step-by-step guide will inform you which one is best suited for your needs.

Fire Classes

Fires fall into one of 6 classes, dependent upon which energy source is fuelling them.

Class A – Fires involving wood, textiles, paper, plastics and other everyday material found in both the home and commercial settings such as warehouses and offices

Class B – Fires involving flammable liquids such as petrol, diesel or oils found on petrol stations, in vehicle service areas and chemical factories

Class C – Fires involving flammable gases such as propane and butane, found in laboratories, chemical plants or manufacturing environments

Class D – Fires involving metals such as aluminium, magnesium and titanium, some of which can be used during welding or chemical processes

Electrical (Class E) – Fires involving electrical equipment and components and can happen anywhere where electrical appliances are used

Extinguisher Types

Each of these fire classes has its own unique set characteristics and challenges to overcome in order to be fully extinguished. As a result several types of Fire Extinguisher have been developed to safely and effectively tackle each fire class.

Water Fire Extinguishers

These are the most economical and widely used fire extinguishers and can be found in offices, schools, hotels and warehouses. Used to tackle the fires of freely combustible materials such as paper, plastic and fabrics. Under no circumstances must water extinguishers be used on electrical or Class F fires as electrocution or a dangerous oil expansion can occur. Water Fire Extinguisher labelling is RED Foam Spray Extinguishers – Foam creates a barrier between the burning material and the air thus starving it of oxygen and extinguishing the fire. More versatile than water, foam fire extinguishers can be used on both Class A and B (flammable liquids) fires. It can also be used to fight electrical fires but it is not recommended as it will cause irreversible damage to electrical components. Foam Fire Extinguisher labelling is YELLOW/CREAM.

Dry Powder

Often the choice of commercial premises for its ability to tackle the majority of common workplace fires. ABC Powder Extinguishers are suitable for Class A, B, C and Electrical fires. They are not suitable for kitchen fires involving the burning of oils and fats and precaution should always be taken not to inhale the powder. For this reason we do not recommend ABC Powder Extinguishers for use in small spaces. Powder Fire Extinguisher labelling is BLUE.

Wet Chemical

These are specialised extinguishers for the use with fat or oil based fires often associated with kitchens. They are potentially hazardous to the user as they can produce harmful, toxic fumes. The chemicals in them bond with the ignited oil or fat producing an emulsion or a cake of soap that starts to cool and extinguish the fire. Wet Chemical Extinguishers can also be used on Class A and B fires. Wet Chemical Fire Extinguisher labelling is ORANGE/YELLOW

CO² Extinguishers

Due to the fact that these extinguishers use carbon dioxide gas as a fire suppressor they are ideal for tackling electrical fires as the electricity cannot conduct via the gas and electrocute the user. Care should be taken as the compressed carbon dioxide, when released, is extremely cold and can cause cold burns if sprayed upon naked skin or if the user should hold onto the extinguisher cone for any length of time. The use of co2 in small spaces should also be avoided if possible as it will lower the available oxygen in the room which could lead to breathing difficulties. Carbon Dioxide Extinguishers can also be used on Class B fires. Carbon Dioxide Fire Extinguisher labelling is BLACK

Fire Extinguisher Care and Maintenance

Every 12 months from the time of initial installation Seton recommends that your Fire Extinguishers are inspected by a trained professional. Due to the high pressures inside the main extinguisher canister there is constant stress on the valves and seals which over time may result in a loss of internal pressure and reduced ability to properly release the fire suppressing contents. Liquid filled extinguishers can be subject to rusting and powder filled extinguishers can absorb moisture and become ‘caked’ resulting in possible malfunction. Fire Extinguishers should also undergo a 6 monthly visual check for any external damage or signs of tampering.